作者ANN0504 (我要快乐)
看板TransBioChem
标题[问题] 普化
时间Sat May 15 23:49:15 2010
1.The mole fraction of sodium hydroxide in a saturated aqueous is 0.310 .
What is the molality of the solution?
(A)0.301m (B)0.690m (C)1.24m (D)12.4m (E)25.0m
2.Which of the following is accturate comparison of the properties of
nitrogen and oxygen?
(A)Nirtogen is more reactive than oxygen.
(B)Nitrogen does not form naturally-occurring ompounds,but oxygen does.
3.Account for the following facts:
(a)CaF2 is insoluble in water,but NaF is quite soluble.
(b)Molten BeCl2 is a poor electrical condunctor,whereas molten CaCl2 is an
excellent one.
找了很久,实在不懂
@ @有点多~谢谢各位
--
*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~
You can give without loving,
but you can't love without giving.
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 61.58.177.56
1F：推 cen71:回第一题..设水为1mol，从莫耳分率可得NaOH为0.45mol 05/16 19:52
2F：→ cen71:molality.为0.45(NaOH之mol数)除18(水之体积，因设水为1mol) 05/16 19:55
3F：→ cen71:再乘上1000(分母为L)可得解为 25.0m 05/16 19:56
4F：推 a12henry:第二题感觉两个都错@@ 05/17 00:42
5F：→ a12henry:第三题a 要水解要克服分子间作用力和溶剂间分子间作用力 05/17 00:44
6F：→ a12henry:还有EN上升 溶解性会增加 所以CaF2分子量较大 要克服的容 05/17 00:45
7F：→ a12henry:剂间作用力较大 而且EN较小 较不容易水解 05/17 00:46
8F：→ a12henry:b的话应该是EN差吧 EN差较大 较易解离 导电性上升 05/17 00:47
9F：推 cen71:我也觉得第二题都错..O2的活性大於N2..自然界也有N化合物 05/17 01:05